Articulated Kneeboard for Concrete Finishers

ABSTRACT

A kneeboard for concrete worker has a knee pan which contains a cushioned knee pad, and a toe pan. The pans are interconnected by links which permit them to pitch with respect to one another, so that the pans can remain flush even when they are on different non-coplanar surfaces. This enables a concrete finisher to move over steps and obstacles without damaging the surface of the concrete.

This application claim benefit of provisional patent application60/932,152, filed May 29, 2007.

BACKGROUND OF THE INVENTION

This invention relates to a kneeboard for concrete finishers.

After concrete pads are poured, while they are still wet, they have tobe finished to have a smooth, flat surface.

Prior inventors have proposed various kneeboards, all intended to permita worker to move about a wet concrete floor without sinking into it, soas to minimize disturbance to the floor surface while it is beingfinished. Representative patents include U.S. Pat. No. 6,347,404 toIskra, U.S. Pat. No. 5,125,479 to Nemes et al., U.S. Pat. No. 4,789,046to McDowall, U.S. Pat. No. 4,747,470 to Fernandez and U.S. Pat. No.4,346,784 to Hammond.

U.S. Pat. No. 2,719,576 discloses a knee-board for cement finishers.There is a single strap, halfway between the knee pad and the toeholder.

U.S. Pat. No. 3,025,526 discloses a kneeling device which straps to theleg, behind the knee and the ankle. There is a link which can pivot andwhen it does, the knee socket slides along the board.

U.S. Pat. No. 6,347,404 discloses a cement finishing board which has afloating knee holder in combination with a toe holder.

U.S. Pat. No. 3,084,458 shows a two-part float, with one part for theknee and one for the toe.

While all of the above are useful, they do not solve a common problem:that of negotiating steps and obstacles on uncured concrete surfaces.

SUMMARY OF THE INVENTION

An object of the invention is to provide a comfortable kneelingapparatus for a concrete floor finisher, designed so that all parts ofthe apparatus remain flush with the floor surface even as the workermoves over an obstacle such as step between surfaces of differentheights. A related object is to keep the weight-supporting components ofthe apparatus flush with the respective surfaces, so as not to mareither, and also to protect the top edge of the step from damage.

The present invention differs from the above patents in that it hasarticulated front and rear pans joined by a pair of links which permitthe pan at either end to pitch or pivot with respect to the other.

These and other objects are attained by a kneeboard for a concreteworker, as described below.

We use the aeronautical terms pitch and roll to define possiblemovements of the pans of this invention, with respect to thelongitudinal axis of the device which is defined as an imaginary linedrawn between the centers of the two pans.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings,

FIG. 1 is an isometric view of an articulated kneeboard embodying theinvention;

FIG. 2 is a top plan view thereof, and

FIG. 3 is a front elevation thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENT

As shown in FIGS. 1-3, an articulated kneeboard embodying the inventionhas two major components: a knee pan 10 and a toe pan 30. The knee pancontains a resilient knee pad 12, which is secured to the pan by abracket 14 in a way that makes pad replacement possible when the padbecomes wet, worn or dirty.

The toe pan 30 is smaller than the knee pan, and has an elevated railing32 supported by four tabs 34 which extend upward from the sides 36 andends 38 of the pan. The depth of the pan is about two inches and therailing, which preferably is made from ¼″ round stock, is about and inchabove the top of the pan. The railing circumscribes an irregular polygondesigned to receive the toe of a worker's boot.

The two pans are interconnected by at least one articulating link,preferably by a pair of laterally spaced links 20 that are attached byjoints such as pins or bolts 22 at either end to the left and rightsides 12, 14 of the pans. The pins or bolts pass through holes formed inU-shaped brackets 40 affixed to the opposed front and rear walls of thetoe and knee pans, respectively. The pins or bolts define axes “A” and“B” about which each pan can pitch with respect to the other pan. On aflat floor, the pans remain coplanar and do not need to pitch withrespect to one another; however, the fact that they can pitch enablesthem to remain flat on the floor even when they straddle a step “S”(FIG. 3) between floors of different heights. That is a particularadvantage of this invention.

While pin-type joints are presently preferred, it should be understoodthat other types of joints such as universal ball joints could be used,and in fact those might be preferable for certain applications. Balljoints would enable the pans not only to pitch relative to one another,but also to roll relatively, in which case the articulated kneeboardcould straddle a step between non-parallel (skewed) surfaces, whilenevertheless remaining flush with each surface.

Preferably, the links can be adjusted for length to accommodatedifferent size users. In the example illustrated, each link has twotelescoping parts 23, 24 can be incrementally adjusted by inserting oneor more pins or bolts 26 into selected spaced holes 28 in thetelescoping parts. Alternative length adjustment schemes might be used.For example, the telescoping parts could be joined by helical threads sothat their combined length could be changed by turning one with respectto the other.

It is also conceivable that the two links illustrated might be replacedby a single element, for example a broad horizontal plate having hingesat either end, or a bar having universal joints (e.g., ball-and-socket)at either end.

An accessory holder 50 is preferably affixed to the front end of theknee pan, to provide a convenient receptacle or retainer for beveragecontainers, tools, product cans and the like. The illustrated accessoryholder has four upwardly extending fingers 52 to retain a containerwithin the holder as the worker moves about. The holder is connected tothe knee pan by bolts 54.

The depth of the knee depression is about two inches, and the centerlines of the links are slightly lower. These preferred dimensions arenot critical and can be varied if necessary to provide a particularclearance as the link passes over step edges. The link could be archedvertically, if desired, to increase that clearance.

Each of the pans is made of sheet metal, and has a broad, flat bottomsurface with upwardly bent left and right sides. Sloping surfaces leadinto the flat bottom at its front and rear.

Strap-retaining slots 56 are formed in each of the left and right sidesof each pan. Flexible fabric straps (not shown) are inserted through theslots.

In use, a worker straps the knee pan to one shin so that the knee isheld against the knee pad, and places his toe in the toe pan. While theperson is working on the floor, his weight is broadly distributed by thelarge areas of the pans, particularly the knee pan, which bears most ofhis weight as he leans forward. The knee pan is therefore the larger.

Because the flat bottoms of the articulated kneeboards can always remainflush against the surface on the concrete slab, less time is needed onthe job fixing the bumps and creases that makeshift solutions usuallycause.

The materials and dimensions mentioned above are merely preferred, andit should be understood that modifications and variations are expected.For example, the pans might be made of a non-metallic material. Sincethe invention is subject to modifications and variations, it is intendedthat the foregoing description and the accompanying drawings shall beinterpreted as only illustrative of the invention defined by thefollowing claims.

1. An articulated kneeboard for concrete finishers, said kneeboardcomprising a knee pan, a toe pan, and structure interconnecting saidpans in a way that permits each of the toe pans to pivot with respect tothe other about at least one axis, whereby the pans can rest flush onrespective non-coplanar surfaces.
 2. The invention of claim 1, whereinthe interconnecting structure is a pair of laterally spaced links, eachextending between the knee pan and the top pan, and the links areconnected to each pan by a movable joint.
 3. The invention of claim 2,wherein each movable joint is a pin joint.
 4. The invention of claim 2,wherein each movable joint is a universal joint.
 5. The invention ofclaim 2, wherein each of said links is length adjustable.
 6. Theinvention of claim 1, further comprising a resilient knee pad secured insaid knee pan.
 7. The invention of claim 1, further comprising anaccessory holder attached to said knee pan.
 8. The invention of claim 1,wherein each of said pans has a broad flat bottom.
 9. The invention ofclaim 8, where the knee pan has sloping surfaces extending front andrear from said flat bottom.
 10. The invention of claim 1, wherein eachof the pans has slots for receiving respective retaining straps.
 11. Theinvention of claim 1, wherein said pivot axis is transverse to alongitudinal axis extending between said pans.